The invention relates to methods and device for repairing breaks in impact resistant windows such as windshields and other glass, including vertical glass (i.e., vertically-oriented glass such as storefront windows). More particularly, the invention relates to a device and repair methods that are capable of repairing many types of damage to glass including, cracks, bulls-eye breaks, star breaks, and angle wing breaks.
Impact-resistant glass used in automobiles typically is a laminate consisting of a layer of an energy-absorbing safety film, e.g., plasticized polyvinyl butyral, that is sandwiched between two layers of flexible plastic substrate, such as polyethylene terephthalate (PET) sheets. Breaks and cracks typically affect only the outer layer of the laminate. Breaks include damage such as bulls-eye breaks, star breaks, and angle wing breaks. The term cracks refers to elongated fractures. When breaks and/or cracks occur, the glass can be replaced. However, a less expensive alternative is to repair the break or crack.
In general, breaks and cracks in impact resistant glass such as a windshield are repaired by replacing the air in a broken area with a resin having a refractive index that matches the outer plastic layer. Resins that are useful for glass repair are well known to the art. Most systems on the market today apply a layer of resin directly over the broken area. Then, a vacuum is created to pull the air out of the break through the resin. The resin then is pulled into the void left by the vacuum and then cured with ultraviolet light. A shortcoming with this conventional setup is that because the air is withdrawn from the break after the resin is applied, the resin tends to block the travel of air out of the break, thereby requiring more time and leading to trapped air. Additionally, conventional setups are not able to address any trapped water in the broken area, which may occur due to direct precipitation, or a windshield being washed or subjected to the morning frost or dew. If the resin is first placed directly over the break without the break being completely dry, then not only does the air get filtered through the resin over the break but moisture will also be drawn through the resin to contaminate or weaken it.
Patents discussing methods and devices for repairing glass damage include U.S. Pat. No. 4,681,510 to Birkhauser, III; U.S. Pat. No. 4,775,305 to Alexander, et al.; U.S. Pat. No. 4,776,780 to Banks, U.S. Pat. No. 5,234,325 to Hill; U.S. Pat. No. 5,897,882 to Gonzalez et al.; U.S. Pat. No. 5,954,901 to Henderson.
Shortcomings of existing methods include dripping of the resin during the repair. Furthermore, conventional systems use a form of a gravity feed with pneumatic pressure, i.e., pressure by a gas, or an action by hydraulic pressure, i.e., pressure by a liquid. They have the disadvantage of either 1) not being able to evacuate existing air in the void completely, or 2) not having the ability to remove all air prior to resin application. Pneumatic pressure systems tend to be slower than hydraulic pressure for two reasons. First, the resin is used to displace air which also will mix with any moisture in the break, thereby contaminating the resin. Second, pneumatic pressure systems cannot force the resin into tight breaks as easily as hydraulic pressure systems, due to reduced pressure compared to hydraulic pressure. As a result, previous systems cannot repair glass in a timely manner, and the quality is questionable. Thus, what is needed is a repair method and device that avoids these and other shortcomings of conventional glass repair devices and methods.
The invention, which is defined by the claims set out at the end of this disclosure, is intended to solve at least some of the problems noted above. In a preferred version of the invention, a repair device is provided for repairing breaks and cracks in a substrate such as glass, windshields, vertical glass, and the like. Breaks include, but are not limited to, bulls-eye breaks (which are circular breaks moving out away from the impact point at a 45-degree angle, giving a characteristic circular dark spot), star breaks, and pock marks. Cracks include elongated fractures. Vertical glass refers to glass that is situated in a plane that is substantially upright. Unlike conventional glass repair devices, the configuration of the repair device according to the invention does not need to be altered in order to fix breaks or cracks. Furthermore, it does not rely on gravity to feed the resin. An exemplary version of the repair device has a piston assembly including a piston, a piston casing, and a piston casing receiver; a mounting bracket; and a suction unit including a manual vacuum pump and a vacuum gauge.
Breaks include damage such as bulls-eye breaks, star breaks, and angle wing breaks. The term cracks refers to elongated fractures. In a preferred method of operating the repair device for break repair, the resin is put into the piston assembly and applied to an air-evacuated break. For a preferred crack repair method, the resin is forced into a crack with hydraulic pressure followed by pneumatic pressure if desired or hydraulic pressure if the crack is too tight to accept pneumatic pressure.
An exemplary repair device for repairing breaks and cracks in a substrate has a piston assembly, a mounting bracket and a pump unit. The piston assembly has a piston, a piston casing and a piston casing receiver. The piston has a proximal end and a distal end. The piston casing has an inner surface and an outer surface, wherein the piston casing receives the distal end of the piston thereby forming a resin-holding gap between the distal end of the piston and the inner surface of the piston casing. The piston casing receiver has an inner surface and outer surface, wherein the outer surface of the piston casing and the inner surface of the piston casing receiver define a clearance, wherein the piston casing receiver has a proximal end and a distal end, wherein the distal end has a first opening that is continuous with the clearance, and wherein the piston casing receiver has a continuous side wall that has a second opening therein disposed remote from the distal end of the clearance. The mounting bracket is removably connected to the piston casing receiver for placement on the substrate. The mounting bracket has a bracket plate, a suction device for mounting the bracket plate to the substrate and an aperture in the bracket plate for receiving the piston casing receiver. The pump unit is removably connected to the second opening of the piston casing receiver. The pump unit is for creating a vacuum in the clearance of the piston assembly.
The windshield repair device allows much faster repair of windshield breaks and cracks. The repair device can be used in the three different manners: (1) a pneumatic pressure mode, where gas is used pushed the resin into a crack or break; (2) a hydraulic mode, in which the piston casing is used as an hydraulic to push the fluid resin into the crack or break; and (3) vacuum mode, in which the resin is pulled into an air-evacuated break. Hydraulic action is defined as when the piston is turned clockwise into the piston casing to push the resin out of the resin-holding gap. The repair device can also be used for repairs on vertical glass including storefronts, i.e., the glass on the side of a store or other building pock marks.
Further advantages, features, and objects of the invention will be apparent from the following detailed description of the invention in conjunction with the associated drawings.